3) pentagrammic prism 2 5/2|2 dual: pentagrammic dipyramid (4.4.5/2), dihedral group D5, χ=2, D=2 V=10, E=15, F=7=5{4}+2{5/2} α γ a b c ρ/R r/ρ l/ρ h/r {4} 45.0 77.3786 43.56 77.06 72.00 0.724617 0.309017 0.951057 3.077684 {5/2} 72.0 25.2428 43.56 46.44 18.00 0.724617 0.951057 0.951057 0.324920